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Ampeg PR-410HLF Crossover Bulbs Needed!

Tube Amps Rule

Tube Amps Rule

Aug 9, 2014
131
287
56
San Diego, CA
#1
Hey all -

Has anyone ever been able to source the bulbs on the crossover pictured?

Ampeg Tech Support was not able to help.

Both are blown and the tweeter is not working.

Thanks in advance!

Pete

IMG_20160921_141525.jpg
 
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#2
Bulbs? Or are they Fuses? I don't know for sure.
I've seen bulbs used for current limiting and maybe that's what is happening here?
Seems odd though to do that in a speaker circuit. It is Ampeg however.
If they are fuses and you asked Ampeg for bulbs, that may explain why they couldn't help.
Maybe try them again and ask about those two little glass thingies on the crossover board.
It looks like the upper one is labeled JWOPT1 and maybe the other is JWOPT2, you might ask Ampeg about those designations.
I'm surprised they weren't more helpful.

-edit- Now that I look at it closer, I see a JWOPT2 to the right (vertical orientation in the pic) and that looks to be just a jumper wire JW= Jumper Wire? The JWOPT1 appears to be just below the top glass thingy and looks like a jumper wire. I'm back to guessing the glass thingies are fuses.
 
#3
Old Garage-Bander said:
Bulbs? Or are they Fuses? I don't know for sure.
I've seen bulbs used for current limiting and maybe that's what is happening here?
Click to expand...
They are bulbs used to take the current from your tweeter, almost all cabs use them. And if you are really cranking it sometimes you can see cabs glow. :woot:
Most of them you can get at auto parts stores, but I could not find a number for them. :banghead:
Maybe @beans-on-toast will know? He knows Ampeg. :help:
:cigar:
 
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#4
It's a limiting light bulb.


The schematic indicates that it is a 36V bulb but there isn't a part number, that would be on the bill of materials (called BOM). I would call customer service back and ask for the crossover bulbs for your speaker cabinet. If that doesn't pan out, PM Hodgy here on TB for assistance.
 
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#8
S-Bigbottom said:
They are bulbs used to take the current from your tweeter, almost all cabs use them. And if you are really cranking it sometimes you can see cabs glow. :woot:
Most of them you can get at auto parts stores, but I could not find a number for them. :banghead:
Maybe @beans-on-toast will know? He knows Ampeg. :help:
:cigar:
Click to expand...
Thank you kind sir for the info.
I guess it a became a slo blo, no glow, where'd the music go? kind of thing. :whistle:
 
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#9
These bulbs have a tungston filament. The resistance is low when cold and increases as the current increases. This way, the bulb acts as a current limiter. Although they are commonly used in crossovers, bulbs aren't the best approach. The problem is, it would be better if they reacted faster to surges but they are cost effective.

On some cabs you can see the bulbs flashing. If the cab has a rheostat to control the level of the high frequency driver, turn it down if you see the lamp flashing.

On this model, you see four spaces for bulbs. The early revision used four 12V 1A bulbs. The two 36V bulbs proved better.
 
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#10
So I realize this is a pretty old post, but how in the hell did you get the pr410 open? I took off the 6 hex head screws, but how did you get the grill off? Is it glued? It doesn’t seem to want to budge. Any suggestions?
 

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